A sample of radioactive waste has a half-life of 10 years and an activity level of 2 curies. After how many years will the activity level of this sample be 0.25 curie?

Which describes increasing the efficiency of energy resource

An element becomes a positively charged ion when itloses protons.loses electrons.gains electrons.gains neutrons.

Aman is trying to drag a small tree that he cut down. if the static coefficient of friction of the tree on the ground is 0.5 and the tree weighs 670 n, what is the minimum amount of horizontal force that the man will need to apply so that the tree will start moving? o a. 465 n o b. 230 n o c. 670 n o d. 335 n